Corrigendum: Identification of volatile organic compounds in extremophilic bacteria and their effective use in biocontrol of postharvest fungal phytopathogens.

[This corrects the article DOI: 10.3389/fmicb.2021.

Microbial and Chemical Characterization of Natural-Style Green Table Olives from the Gordal, Hojiblanca and Manzanilla Cultivars.

Microbial and biochemical changes in the brine during the spontaneous fermentation of Gordal, Hojiblanca and Manzanilla olive cultivars processed according to the natural style were monitored. The microbial composition was assessed through a metagenomic study. Sugars, ethanol, glycerol, organic acids and phenolic compounds were quantified by standard methods.

Microbial community and volatilome changes in brines along the spontaneous fermentation of Spanish-style and natural-style green table olives (Manzanilla cultivar).

Microbial community and volatilome of brines were monitored during the spontaneous fermentations of Spanish-style and Natural-style green table olives from Manzanilla cultivar. Fermentation of olives in the Spanish style was carried out by lactic acid bacteria (LAB) and yeasts, whereas halophilic Gram-negative bacteria and archaea, along with yeasts, drove the fermentation in the Natural style. Clear differences between the two olive fermentations regarding physicochemical and biochemical features were found.

Effect of Spanish-Style Table Olive Processing on Fatty Acid Profile: A Compositional Data Analysis (CoDA) Approach.

This manuscript considers that the composition of Manzanilla and Hojiblanca fats are compositional data (CoDa). Thus, the work applies CoDa analysis (CoDA) to investigate the effect of processing and packaging on the fatty acid profiles of these cultivars. To this aim, the values of the fat components in percentages were successively subjected to exploratory CoDA tools and, later, transformed into (isometric log-ratio) in the Euclidean space, where they were subjected to the standard multivariate techniques.

Quality parameters and fatty acid and triacylglycerol profiles of directly brined table olive fat throughout processing and shelf life.

The transformations that may suffer directly brined table olive fat during processing were studied using cracked Aloreña de Málaga olive as a model. The classical studies showed that storage increased acidity and K, but not peroxide value, K and ΔK. FA profiles, nutritional fat subclasses, and TAGs suffered several significant changes along processing, although some could be spurious.

Identification of Volatile Organic Compounds in Extremophilic Bacteria and Their Effective Use in Biocontrol of Postharvest Fungal Phytopathogens.

Phytopathogenic fungal growth in postharvest fruits and vegetables is responsible for 20-25% of production losses. Volatile organic compounds (VOCs) have been gaining importance in the food industry as a safe and ecofriendly alternative to pesticides for combating these phytopathogenic fungi. In this study, we analysed the ability of some VOCs produced by strains of the genera , , , and to inhibit the growth of , , , , , and , and .

Multi-Statistical Approach for the Study of Volatile Compounds of Industrial Spoiled Manzanilla Spanish-Style Table Olive Fermentations.

Table olives can suffer different types of spoilage during fermentation. In this work, a multi-statistical approach (standard and compositional data analysis) was used for the study of the volatile organic compounds (VOCs) associated with altered (butyric, sulfidic, and putrid) and non-altered (normal) Manzanilla Spanish-style table olive fermentations. Samples were collected from two industrial fermentation yards in Seville (Spain) in the 2019/2020 season.

Production of volatile compounds by wild-type yeasts in a natural olive-derived culture medium.

The production of volatile compounds in naturally fermented green table olives from Manzanilla cultivar was investigated. A total of 62 volatile compounds were detected after 24 weeks of fermentation. To clarify the contribution of yeasts to the formation of these compounds, such microorganisms were isolated from the corresponding fermenting brines.

Impact of Processing and Extraction on the Minor Components of Green Spanish-Style Gordal Table Olive Fat, as Assessed by Innovative Approaches.

This work aims to study the effect of the green Spanish-style table olive processing and extraction method of fat on its minor components. For this purpose, it uses standard multivariate analysis (developed for Euclidean space), Compositional Data (CoDa) analysis (for data in the simplex) and Multiple Factor analysis (MFA). Overall, processing had a scarce effect on most of the minor components except ethyl and methyl esters and diacylglycerols, which markedly increased during fermentation; however, these compounds in table olive do not have the negative connotations that those in olive oil do since they are normal metabolites from the yeast microflora habitually present during the process.

Aroma profile and volatile composition of black ripe olives (Manzanilla and Hojiblanca cultivars).

The aroma profile and volatile composition of 8 samples of black ripe olives from Manzanilla and Hojiblanca cultivars were analyzed with the aim to characterize this type of table olive. The aroma of samples was described by a sensory panel using quantitative descriptive analysis (QDA), whereas the volatiles were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). Eleven odor descriptors (briny, sautéed mushroom, earthy/soil-like, oak barrel, nutty, artificial fruity/floral, natural fruity/floral, vinegary, alcohol, fishy/ocean-like, and cheesy) were evaluated, of which only one descriptor (briny) showed a significant difference between cultivars.

Panel and Panelist Performance in the Sensory Evaluation of Black Ripe Olives from Spanish Manzanilla and Hojiblanca Cultivars.

There is vast experience in the application of sensory analysis to green Spanish-style olives, but ripe black olives (≈1 × 10 kg for 2016/2017) have received scarce attention and panelists have less experience on the evaluation of this presentation. Therefore, the study of their performance during the assessment of this presentation is critical. Using previously developed lexicon, ripe olives from Manzanilla and Hojiblanca cultivars from different origins were sensory analysed according to the Quantitative Descriptive Analysis (QDA).

Changes in volatile composition during the processing and storage of black ripe olives.

The present study revealed the effects of each step of black ripe olive processing (preservation, darkening, packing + sterilization) and storage on the volatile composition of two olive cultivars (Manzanilla and Hojiblanca). The preservation step enriched the volatile profile of the olives, mainly in ethyl acetate, methyl acetate, and ethanol. The darkening step produced the total or partial elimination of 55-65% of the volatiles identified before this step.

Microbiota and Metabolite Profiling of Spoiled Spanish-Style Green Table Olives.

The aim of the present study was to assess the malodorous spoilages of Spanish-style green table olives through microbial and metabolite composition using current measuring techniques (e.g., high-throughput DNA sequencing, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry).

Effect of Spanish-style processing steps and inoculation with Lactobacillus pentosus starter culture on the volatile composition of cv. Manzanilla green olives.

The effects of the main steps of Spanish-style processing (alkaline treatment and fermentation) on the volatile composition of cv. Manzanilla green olives were studied. Both spontaneous and controlled fermentations were considered.

Assessment of the Minor-Component Transformations in Fat during the Green Spanish-Style Table Olive Processing.

There is an increasing interest of consumers for natural and healthy products. This work assesses the transformations that green Spanish-style processing of Manzanilla and Hojiblanca table olives produces on the minor components of their fat. Discriminant analysis showed that most of the variability was not due to processing (24.

Effect of post-fermentation and packing stages on the volatile composition of Spanish-style green table olives.

The volatile profile of Spanish-style green table olives after fermentation and the changes in volatile compounds that occurred as a result of the post-fermentation and subsequent packing stage were explored by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS). Three olive cultivars (Manzanilla, Gordal, and Hojiblanca) were processed and olive samples were taken at three different times throughout the elaboration: after fermentation, after post-fermentation, and after packing. A total of 132 volatile compounds were identified, including 10 phenols, 25 alcohols, 11 acids, 39 esters, 8 hydrocarbons, 14 carbonyl compounds, 17 terpenes, and 6 other compounds.

Effect of green Spanish-style processing (Manzanilla and Hojiblanca) on the quality parameters and fatty acid and triacylglycerol compositions of olive fat.

This work studies the effect of processing Manzanilla and Hojiblanca olives as green Spanish-style on the quality parameters and fatty acid and triacylglycerol compositions of their oils. Lye treatment reduced the values of most quality parameters while fermentation/packaging increased acidity, K232 and K270. Processing did not cause any systematic effect on fatty acids (FA), triacylglycerols or nutritional fat subclasses but significant differences between cultivars were observed.

Mechanisms involved in the antiproliferative and proapoptotic effects of unsaponifiable fraction of extra virgin olive oil on HT-29 cancer cells.

Extra virgin olive oil (EVOO) has demonstrated great oncostatic and antiinflammatory properties. Nowadays, it is clear that unsaponifiable fraction (UF) as well as other minor EVOO components have a key role in these beneficial effects. The present study was designed to evaluate UF effect in HT-29 human colon adenocarcinoma cells.

Chemometric classification of the fat residues from the conditioning operations of table olive processing, based on their minor components.

The work characterizes the unsaponifiable matter of fats released in pitting green (GP) and ripe (RP) olives, in pitting/stuffing green olives with vegetable (GPSV) and animal (GPSA) products and in the fat settled at the end of the factory sewer system (W). The unsaponifiable matter ranged from 1.94% (RP) to 5.

Chemometric characterisation of the fats released during the conditioning processes of table olives.

This work deals with the characterisation of five fat types released during the conditioning process of table olives, pitting green olives (PGF), pitting ripe olives (PRF), pitting/stuffing green olives with vegetable origin products (PSGVF) and pitting/stuffing green olives with animal origin materials (PSGAF) along with the fat collected at the end of the factory sewer (WF). The parameters analysed included: acidity, peroxide value, spectrophotometric measurements (K232, K270 and ΔK), fatty acid composition of the raw material and the neutral fat, triacylglycerol composition of the neutral fat as well as the proportion and composition of the polar fraction. A chemometric analysis of specific groups of compounds was able to establish differences among the types of fats; the overall analysis showed two major groups: PGF, PRF and PSGVF were only moderately degraded, and PSGAF and WF were highly degraded.

Influence of ripe table olive processing on oil characteristics and composition as determined by chemometrics.

The changes in ripe olive fat produced by processing were studied according to cultivars using the general linear model, principal component analysis (PCA), predictive discriminant analysis (DA), and hierarchical clustering. Acidity, peroxide value, K(270), and DeltaK increased during storage. Acidity also increased after sterilization, whereas K(270) decreased after darkening; K(232) showed a progressive decrease during processing.

Survey of vitamin B(6) content in commercial presentations of table olives.

For nutritional purposes, a survey of the vitamin B(6) levels from a variety of commercial presentations of table olives was carried out, taking into account the three main processing types (Spanish-style, directly brined, and ripe olives). The analysis was performed by HPLC, following the official French method for vitamin B(6) determination in foodstuffs. In-house validation data for two commercial table olives showed that the method precision was good (coefficient of variation <6%) and recovery was quantitative (104% on average).